1. Field of Invention
The present invention relates to a system and method for observing the heart rate of a passenger, which can exactly measure the heart rate of a passenger and provide a health care service corresponding to the measured heart rate.
2. Description of Related Art
Research into technology for providing health, safety and convenience services based on biometric signals in a vehicle has been active. The demand for measurement technology that measures various biometric signals, especially, the heart rate, has increased. The reason for this is that the heart rate of a passenger reflects both the physical and mental state of the passenger, so that the heart rate may be a basis for the provision of new services.
Various heart rate sensing methods in a vehicle environment have been evaluated. Representatives sensing methods include an electrocardiogram (ECG), a ballistocardiogram (BCG), a phonocardiogram (PCG), a photoplethysmogram (PPG), etc. These methods sense the heart rate using different principles. In a series of procedures in which a heart beat starts at the stimulation of a heart muscle cell and causes variations in a blood flow, electrical, mechanical, and optical signals are generated, so that the heart rate can be detected using various methods.
However, to date, none of the above methods have so far been applied to actual vehicles. The most difficult thing is that a relatively weak heart rate signal is easily contaminated by noise sources, such as vibration noise or the motion of a passenger, due to the influence of various environment variables present in the vehicle environment. As a result, the period of an available heart rate signal is shortened, so that the shape of the signal discontinuously appears, thus causing a decrease in the amount of extractable information.
This problem may be solved by employing a method that uses a combination of different sensors immune to specific environment variables, juxtaposes the sensors at various locations, and then recombines the signals. The present invention is intended to present such a method. This method enables the heart rate to be more robustly sensed in a vehicle compared to a single sensor-based measurement, so that the state of the passenger can be easily analyzed. In addition, a larger amount of information about the state of the passenger can be extracted by comparing the synchronization information between individual signals. Feedback suitable for the state of each individual person is provided based on the extracted state information, thus promoting the safety and convenience of the passenger with higher performance.
For example, JP 2011-024902 A presents a technology for selecting a single measurement result from among a plurality of measurement results and taking ECG measurements, but it is merely configured to make a simple comparison based on the amplitude or Signal to Noise (S/N) ratio and select any one signal. Accordingly, this technology is actually insufficient for application to a technology for stably measuring, evaluating, and selecting various types of signals related to the heart rate.
Further, KR 0736721 B also presents a technology for installing sensors at locations corresponding to the shoulders and the hips, filtering noise, and amplifying the filtered signals. However, this technology is problematic in that a lot of time is required by the procedure of filtering noise, and the accuracy of measurement is also deteriorated.
The information disclosed in this Background section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.